The invention is based on an electrical manual tool, in particular a power saw.
An electrical power saw of this type has already been proposed (DE 196 25 081 A1), in which the rearward portion of the shaft of the machine housing is embodied as a handgrip, with which the power saw is held during sawing.
The electrical manual tool of the invention has the advantage that as a result of the rod-like design of the entire shaft and the provision of a waist for the shaft end in the transition region to the head of the machine housing, with the attendant reduction in the circumference of the handgrip, an ergonomic, defined gripping position of the electric power tool with a secure hold in the vicinity of the on/off switch is attained. The thumb of the user rests during operation automatically in an ergonomic position on the switch, thus providing increased safety when the power tool is turned off.
By means of the provisions recited in the further claims, advantageous refinements of and improvements to the electrical manual tool of the present invention are possible.
In a preferred embodiment of the invention, a protective rib extending approximately parallel to the tool protrudes from each side of the machine housing on the underside of the head, toward the tool, of the machine housing. These protective ribs serve to protect the fingers and provide a limitation to the fingers of the user, so that they cannot accidentally come into contact with the tool or workpiece.
In an advantageous embodiment of the invention, the front or face end of the machine housing is sloped at a 45 to the shaft axis. Because of this 45 angle of the housing, an auxiliary arrangement in sawing a 45 angle is obtained when the electrical manual tool is used as a fine-cutting saw.
In an advantageous embodiment of the invention, three bearing and fastening points for clamping the machine housing to a miter box are provided on at least one and preferably on each side face of the machine housing; they are arranged such that they form the corners of the triangle. Preferably, the bearing or fastening points have one bearing rib protruding from each side of the housing and two hollow cylinders, passing through the machine housing crosswise to the shaft axis, whose cylinder openings in the housing wall are concentrically surrounded by a bearing collar formed in the housing wall. The clamping of the machine housing to the miter box is done via screws, which are passed through both hollow cylinders; the bearing collars on the cylinder openings of the hollow cylinders assure that the machine housing cannot be braced wrong or destroyed in the clamping process.
In a preferred embodiment of the invention, a retaining device is disposed on the head of the machine housing for a stop, protruding crosswise and extending crosswise along the front of the head. Such a stop has the advantage, when the electrical manual tool is used as a power saw, that the workpiece is pulled against the stop when the saw teeth are oriented for traction, so that safe and precise work is made possible.
In an advantageous embodiment of the invention, the stop is in the form of a rod-like hoop bent into a U, and the retaining device has a hollow cylinder, which passes through the machine housing crosswise to the shaft axis, so that one leg of the hoop can be inserted through it, preferably in form-locking fashion, and also has a channel, molded into the housing wall on the front end of the head of the machine housing near its underside, for bracing the other leg of the hoop that forms the stop. Axial protection to prevent the hoop from being able to fall out of the retaining device is attained, in accordance with an advantageous embodiment of the invention, in that the leg of the hoop that can be inserted into the hollow cylinder has a plunge cut, and a pressure piece is disposed in the machine housing and dips into the plunge cut in form-locking fashion through a recess in the cylinder wall of the hollow cylinder, by means of a compression spring.
In an alternative embodiment of the invention, the leg of the hoop that can be inserted into the hollow cylinder is embodied as long enough that it protrudes out of the machine housing on the side of the housing opposite the insertion side. In the region of its protruding end, this leg of the hoop is provided with a screw thread, onto which a wing nut can be screwed for fixing the leg of the hoop in the machine housing.
All the forms of embodiment of the invention described above serve, in a refinement of the invention, the purpose of ergonomic improvement in manipulating and working with the electrical manual tool.